STINGRAYS

For a couple of days it'd been unusually hot, humid and fairly calm, so that biting gnats called Chaquistas were making working outside a bit hard. But then a norte began blowing in, bringing intermittent showers, temperatures down in the upper 70s and a broody feeling out over the ocean. Maybe that's why on my walk that day I saw things not normally seen. A big flock of parakeets spun overhead; a Peregrine Falcon flew right over my head not 15 feet high, and; stingrays appeared in shallow water right next to the shoreline. You can see a 15-inch-wide one of those above.

First of all, are stingrays "fish?" In the old days when textbooks spoke of "the Class Pisces," or "the taxonomical Class of Fishes," it was easier to say. However, nowadays gene sequencing has revealed that kinds of animals we think of as fishes are so scattered throughout the phylogenetic Tree of Life that, if we consider any one branch including all those taxa, that branch will include certain four- legged animals that definitely we don't think of as "fish." In other words, the concept of "fish" isn't sound in a technical, taxonomical sense.

However, using the term "fish" in a traditional way, we can say that ray-fish are indeed fish. They're "cartilaginous fish" (as opposed to bony fish), which groups them with sharks and skates.

What's the difference between a stingray and a Manta Ray? One definition of a stingray is that it's a member of the Stingray Family, the Dasyatidae. Manta Rays belong to this family, so manta rays also can be regarded as stingrays. Manta rays might be defined as species in the genus Manta, a genus famous for including some of the largest rays. One could say, then, that all mantas are stingrays, but not all stingrays are mantas.

Stingrays bear razor-sharp stingers, or saw-toothed spines, which grow from their whip-like tails like fingernails. Two grooves containing venom-secreting glands occur below the spines. Stingray "wings" are actually large pectoral fins. Many ray-fish lack stingers. Their rear ends look like the rear ends of regular fish. In fact, when you have a lot of pictures of cartilaginous fish before you, you can arrange them so that there's a fairly smooth gradation from cylinder-bodied sharks to flat-bodied ray-fish.

I'm unsure which species appears in my photograph, but I'm leaning toward calling it the Southern Stingray, DASYATIS AMERICANA, despite all the pictures I've seen showing that species as much darker than what's in my picture. Southern Stingrays are common from southern New Jersey south to Brazil. They get up to 5-½ feet wide (1.7 m) so maybe ours is a baby.

While researching my stingrays I came upon some pictures of another species of ray migrating, and those pictures are worth seeing. Take a look here.